Preparation And Properties Of Waterborne Epoxy Resin Concrete Anti-Corrosion Coating Modified By Graphene Oxide

Applying anti-corrosion coatings on the surface of concrete can help improve their durability and extend their service life.Waterborne epoxy resin(WEP)coating is a new type of environment-friendly coating.However,after curing,it will generate a large number of micropores,which limits its widespread application.Previous studies have shown that adding nano particles in the coating can effectively improve the protective performance of the coating.Such as the lamellar structure of graphite oxide(GO)can extend the penetration path of corrosive ions.So this paper uses GO modified WEP to prepare GO-WEP coating,and applies it to the surface of concrete substrate to study its anti-corrosion performance.This article characterizes the microscopic properties of coatings with different GO dosages,and analyzes the influence of GO dosages on the conventional and corrosion resistance properties of coatings,explores the corrosion resistance mechanism of coatings,and determines the optimal GO dosages.The GO-WEP coating based on the optimal dosage is applied to the surface of concrete with two different commercially available WEP coatings at the same dosage,and the corrosion resistance of concrete under chloride salt dry wet cycle,chloride salt freezethaw cycle,and chloride salt immersion test is compared and analyzed.The main research conclusions are as follows:(1)GO and WEP have good compatibility,which can effectively fill the pores of the coating,reduce porosity,improve the cross-linking density of the coating,complicate the penetration path of corrosive media,increase the tortuosity of the diffusion channels in the matrix,and delay the diffusion of corrosive media.After exploring the GO dosage,it was found that GO with a content of 0.3wt% has the best effect on improving the coating.(2)Through chloride salt dry wet cycle,chloride salt freeze-thaw cycle,and chloride salt immersion test,the color difference,adhesion,and pencil hardness changes of the coating after the test are investigated.It is found that the performance of GO-WEP coating is superior to that of commercial coatings.In the chloride salt dry wet cycle test,the color difference of GO WEP coating is 50% lower than the average of commercial coatings,and the adhesion and pencil hardness are 170% and 50% higher than the average of commercial coatings,respectively.In the chloride salt freeze-thaw cycle test,the color difference of GO WEP coating is 12% lower than the average of commercial coatings,and the adhesion and pencil hardness are 109% and50% higher than the average of commercial coatings,respectively.In the chloride salt immersion test,the color difference of GO WEP coating is 20% lower than the average of commercially available coatings,and the adhesion and pencil hardness are 36% and 50% higher than the average of commercially available coatings,respectively.(3)By studying the apparent morphology,mass loss rate,and compressive strength of concrete after chloride salt dry wet cycle,freeze-thaw cycle,and immersion test,it is found that GO-WEP coating has the best protective effect on concrete.The addition of GO results in excellent corrosion resistance of the GO-WEP coating.Therefore,the apparent morphology of the coating remains intact after three corrosion tests,and the difference in mass loss before and after the cyclic test is small.At the same time,the coating can prevent corrosive ions from entering the interior of the concrete,thereby ensuring its durability.